N95 respirators and other medical masks are used in the medical community to protect against respiratory pathogen infections. However, there remains conflicting recommendations on the optimal respiratory protection methodology. Therefore, this multi-site, cluster randomized clinical trial was conducted to evaluate various respiratory protective equipment amongst US outpatient healthcare workers. University of Florida investigators provide statistical support for the primary analyses assessing the effectiveness of different interventions against respiratory infections. This trial also provides a unique dataset to characterize respiratory transmission in a key population, healthcare workers, and several secondary analyses evaluating transmission dynamics are planned.